The stabilization occurs even when the therapy, whose short name is MMF, is administered in doses lower than those used in a previous Phase 2 clinical trial. The latest study is retrospective, which means it is based on patient records from the past rather than the present.

ILD causes thickening of the interstitium, a network of tissue that supports alveoli and through which blood vessels travel in the lungs. Alveoli are air sacs that absorb oxygen from blood and return carbon dioxide to it. ILD and pulmonary arterial hypertension (PAH) are the most frequent causes of SSc worsening and patients dying from it.

The two-year Phase 2 clinical trial (NCT00883129) compared MMF and cyclophosphamide’s (CYC’s) ability to improve lung function. It did not show that MMF was more effective than CYC, but it did indicate that MMF had fewer side effects and scleroderma patients tolerated it better.

The team based their analysis on 46 patients who had used MMF for at least a year between 1997 and 2014. They collected and analyzed data at the beginning of MMF treatment and at 6, 12 and 24 months afterward. The median MMF dose was 1.5 g daily, which was lower than the 3 g a day used in the Phase 2 study.

Researchers found that two measures of lung function — diffusing capacity of lung for carbon monoxide, or DLCO, and forced vital capacity, or FVC — were stable over the course of MMF treatment.

The team used a new computer approach to analyze changes in structural abnormalities in the lungs during treatment. The system, computer-aided lung informatics for pathology evaluation and rating, or CALIPER, showed there were no significant changes,

The team also assessed PAH — measured by right ventricular systolic pressure, or RVSP — in the MMF-treated ILD patients. RVSP was stable over the course of treatment, suggesting that either PAH remained stable because ILD was stable or that MMF could independently control PAH.

“Our study supports previous studies describing the efficacy of MMF in stabilizing lung function in SSc-ILD.” the researchers wrote. “Our study is a real-life experience outside the boundaries of randomization and supports the safety and tolerability of MMF.

“MMF is well tolerated and slows the rate of decline in lung function in SSc-ILD patients, even at doses lower than 3 g/day,” the team concluded.